1. Field of the Invention
The present invention relates in general to automatic transmissions for motor vehicles, and more particularly to automotive automatic transmissions of a type which is equipped with a park-lock mechanism.
2. Description of the Prior Art
One of conventional automotive automatic transmissions of the above-mentioned type is shown in Japanese Patent First Provisional Publication 60-84469. In this transmission, a parking gear which constitutes part of the park-lock mechanism is integral with an input gear mounted on one end of a countershaft of the transmission. Essential parts of the transmission are arranged about a main shaft which is coaxial with the crankshaft of the engine, and the countershaft is arranged in parallel with the main shaft. The torque from the engine is transmitted through the input gear to the countershaft and the torque of the countershaft is transmitted through a final drive gear mounted on the other end of the countershaft to a final drive mechanism. That is, the parking gear is integrally and coaxially formed on one side surface of the input gear of the countershaft. When a parking pawl pivotally held by a transmission casing is engaged with the parking gear, the countershaft is locked and thus drive wheels of the motor vehicle are locked.
However, provision of the parking gear on the side surface of the input gear of the countershaft tends to increase the entire length of the countershaft and thus cause a longitudinally bulky construction of the transmission. In fact, such elongated countershaft narrows an effective space for accommodating other parts of the transmission.